Find keyword, replace next value in Python

Question

I have an input file I want to duplicate with some of the parameters changed. This is a simplified version of the input file:

Temperature = 100
Density = 8
Expansion factor = 1.0

I am trying to write a script that will search through the input file, find a keyword (eg temperature/density), then change the next value after the keyword. I have a series of for loops set up for each keyword but I can't work out how to edit the next value after the keyword. I think I need regex but this is all I have so far:

regex = r"Temperature\s(.*)"
re.findall(regex, file)

I would also like to ignore how many spaces there are in the input file if possible - eg these three lines would all appear the same:

Temperature        =    100
Temperature=100
Temperature = 100

If that's possible!

Answer 1

Something like

your_new_text = re.sub(r"(Temperature\s*=\s*)[^\n]+", "\\1TheNewValue", input_file.read())

should do the trick. Replace Temperature with whatever you are searching for and TheNewValue with whatever you want in it's place